In general, a liquid crystal display apparatus has features such as a small weight, a small thickness, and low power consumption. Therefore, liquid crystal display apparatuses are widely used as display apparatuses for personal computers, portable information terminals, television sets, car navigation systems, and the like. Some liquid crystal display apparatuses are capable of displaying two-dimensional video images and three-dimensional video images.
In a liquid crystal display apparatus, a backlight device is necessary as the light source for illuminating a liquid crystal display panel with light. Depending on the structure of the backlight device, liquid crystal display apparatuses are classified into an edge (side-edge) type and a direct-lighting type.
An edge-type backlight device has light sources at side portions of a light guide plate, and light is emitted from the light sources and is guided by the light guide plate toward the liquid crystal display panel placed in front of the backlight device. A direct-lighting backlight device has light sources behind the liquid crystal display panel when viewed from a viewer.
Among the liquid crystal display apparatuses, there are apparatuses that are capable of displaying video images in display modes with different image qualities, for example. Such apparatuses capable of displaying video images in various display states are required to have backlight devices and display apparatuses that are capable of performing more appropriate backlight control.